My thing with the animation is that it's only good during the fight scenes, outside of that it feels like it's utterly lost on what they want to do when some big sequence isn't happening but still feel like everything needs to be moving for the sake of it.
Most of the gang feel like they're just there. Sokka is either just making random jokes or screaming that they're gonna die. Toph really, REALLY, wants some dick. Zuko is there, I guess. And Katara comes the closest to having a place in the story by, once or twice, wondering if the villain guy is on the up and up.
The Denied just feel like an even more underdeveloped version of the equalists that were tacked on just to give this non-canon shonen movie named henchmen to fight the gang, coming off as particularly whiny and shallow when they're yelling at gang that they don't understand their pain because 'the world hasn't been good to us; NOT LIKE YOU' in-between laughing like maniacs at the mass murder of innocent people. There's no way that Aang's legend doesn't lead with him being the dude so chill and opposed to violence that he spared the Fire Lord's life, yet the Denied characters keep talking about him like they expect him to be a killing machine.
I like the villain overall, though I feel like we could have spent more time fleshing out him and Aang's relationship. Him fucking murdering the entire cast was probably my favourite fight.
The humour misses more than it hits, and when it misses it feels terribly out-of-place. The whole movie is about Aang's guilt and his desperations to preserve his culture, and yet when the Denied are actively destroying what remains of the temple he's trying to preserve, he just reacts like "Oh, come on. Don't do that. That's my stuuuuuuff."
There's so much memberberries in this movie, god damn. Like, every other scene is "Member that character? Member that joke? Member the thing they said? Member cabbage guy? We gotta have three cuts to cabbage guy until he's cabbaging- HE'S CABBAGING ALL OVER!"
After LOK, I have noticed that every show an ATLA alumnus works on, there is the same elements: Very good designs, elements as a power system and a complete failure stemming from wanting to make the show more woke than it already was. Voltron started out as the definitive take on the idea that combined elements from every series and was a love letter only to become boring, waste all its potential and basically insult you for giving a damn.
Only thing I remember about Voltron was all main villains ending up getting retconned as 'Super duper good dudes who got corrupted by evil juice', Lance getting confirmed as basically giving up on life so he can pine over his dead last-minute girlfriend, and many emotional character building scenes with Shiro being made meaningless because it was a fake Shiro the whole time but don't worry he's getting reamed by that random background dude.